FBI Offers Sheriff Help in Slaying Investigation : Crime: The agency says it is monitoring the inquiry into the stabbing of a Japanese businessman in Camarillo. Authorities say they have no strong leads.

The FBI said Thursday that it is monitoring Ventura County’s investigation into the stabbing death of Japanese businessman Yasuo Kato and is ready to step in if the sheriff requests it.

“We’re saying, ‘If you need assistance, we’re here,’ ” said FBI spokesman John Hoos in Los Angeles.

Gary Auer, special agent in charge of the FBI’s Ventura County office, met with sheriff’s investigators for about 30 minutes Thursday morning. But he has declined to comment on the case.

Meanwhile, investigators say they have found no evidence to identify the killer who left Kato dead at his Camarillo home on Sunday.

“It’s a real whodunit,” Sheriff’s Cmdr. Vince France said. “We haven’t got one solid lead in this whole investigation.”

Kato’s body was found Monday in the garage of his house on Arabian Place with a bloodied, jagged-edged hunting knife nearby.

Someone apparently killed him as he unloaded groceries from his Toyota 4-Runner on Sunday night between 9:30 and midnight.

France said Kato had put one armload of groceries on the counter and turned back to the car to get another when he was attacked.

Kato, reportedly a champion martial arts expert, died of two swift, close-spaced stab wounds to the heart.

The coroner found no other injuries or signs of a struggle, leading police to believe that Kato’s attacker either surprised him or was familiar to him.

Sheriff’s detectives have been scouring sporting goods stores in Ventura County in search of similar knives, hoping to learn who purchased the weapon used in the slaying, France said.

But little other evidence has been found, France said.

France said detectives have interviewed Kato’s family and found no information pointing to anyone, including Kato’s relatives, as the killer.

He said they are continuing to check theories that Kato’s death was an anti-Japanese hate crime, or a contract hit directed by the yakuza , as Japanese organized crime syndicates are commonly known.

“We’re not ruling anything out, and I know that sounds trite, but that’s where we’re at,” France said.

On Feb. 9, Kato told police that an unidentified motorcycle rider came to his door claiming to be “an unemployed American worker who lost his job because of the Japanese.”

The man demanded money from Kato, then threatened to kill him after Kato shoved him out of the house and locked the door, according to a sheriff’s report.

But investigators said they also are looking for any connection Kato had to the yakuza.

Experts in Asian crime intelligence said Kato’s wounds could fit the profile of a typical yakuza contract slaying.

“It’d be nice if we could discount one of the two theories,” France said.

“Either to rule out the theory that organized crime did it, or to discount the theory that it was a hate crime, or even to identify the person at the door on the ninth.”

“I don’t think at this point we’re discounting any motive,” said Assistant Sheriff Oscar Fuller, who oversees the investigations unit. “Nor are we focusing on any motive.”